State of the art in CAPTCHAs?

April 27, 2012

CAPTCHAs are a necessary evil. These days there is no lower time-investment trade-off that works as well to prevent automated submissions to comment sections, user registration, and contact forms. That being said, they are not without issues.

First, it’s frustrating. As techniques to automate the usual “type in the letters above” system get more advanced, the visual distortion required to defeat them makes it more difficult for actual humans to decipher the answer as well. I am a big fan of Google’ reCaptcha in theory, but in practice I find myself refreshing the words multiple times before arriving at one that’s legible enough to guess.

Second, there are accessibility concerns. ReCaptcha has addressed this with the most confusing audio version imaginable. From what I can tell, we’re meant to type the words that the recorded voice says loudest, above the background noise of other spoken words.

So that begs the question: what else is out there? Potentially useful alternative KittenAuth made waves 6 years ago but never progressed further. Others like the poorly-designed Catcha have arrived at a similar idea but without taking into real consideration basic statistics (1 in 3 odds isn’t enough), usability, or accessibility.

As far as I’m concerned, reCaptcha remains the best option by default. What else is out there?